﻿/************************************************************************

   Extended Silverlight Toolkit

   Copyright (C) 2010-2012 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://extendedsilverlight.codeplex.com/license

   Please purchase a commercial version of this toolkit if you are using
   it in a commercial product. The commercial versions support the project,
   and also include more features for each control, priority support,
   source code, updates, removed watermark, and a proprietary license.

   Visit http://xceed.com and follow @datagrid on Twitter.

  **********************************************************************/

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Data;

namespace Xceed.Silverlight.Data
{
  internal static class GroupDescriptionExtensions
  {
    internal static IEnumerable<string> GetPropertyNames( this IEnumerable<GroupDescription> collection )
    {
      foreach( GroupDescription description in collection )
      {
        yield return description.GetPropertyName();
      }
    }

    internal static string GetPropertyName( this GroupDescription groupDescription )
    {
      if( groupDescription is PropertyGroupDescription )
        return ( ( PropertyGroupDescription )groupDescription ).PropertyName;

      if( groupDescription is DataGroupDescription )
        return ( ( DataGroupDescription )groupDescription ).PropertyName;

      throw new ArgumentException( "The specified groupDescription must be a PropertyGroupDescription or DataGroupDescription instance.", "groupDescription" );
    }
  }
}
